1 /* 2 * Copyright © 2006 Keith Packard 3 * Copyright © 2007-2008 Dave Airlie 4 * Copyright © 2007-2008 Intel Corporation 5 * Jesse Barnes <jesse.barnes@intel.com> 6 * Copyright © 2011-2013 Intel Corporation 7 * Copyright © 2015 Intel Corporation 8 * Daniel Vetter <daniel.vetter@ffwll.ch> 9 * 10 * Permission is hereby granted, free of charge, to any person obtaining a 11 * copy of this software and associated documentation files (the "Software"), 12 * to deal in the Software without restriction, including without limitation 13 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 14 * and/or sell copies of the Software, and to permit persons to whom the 15 * Software is furnished to do so, subject to the following conditions: 16 * 17 * The above copyright notice and this permission notice shall be included in 18 * all copies or substantial portions of the Software. 19 * 20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 23 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR 24 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 25 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 26 * OTHER DEALINGS IN THE SOFTWARE. 27 */ 28 29 #ifndef __DRM_MODESET_HELPER_VTABLES_H__ 30 #define __DRM_MODESET_HELPER_VTABLES_H__ 31 32 #include <drm/drm_crtc.h> 33 #include <drm/drm_encoder.h> 34 35 /** 36 * DOC: overview 37 * 38 * The DRM mode setting helper functions are common code for drivers to use if 39 * they wish. Drivers are not forced to use this code in their 40 * implementations but it would be useful if the code they do use at least 41 * provides a consistent interface and operation to userspace. Therefore it is 42 * highly recommended to use the provided helpers as much as possible. 43 * 44 * Because there is only one pointer per modeset object to hold a vfunc table 45 * for helper libraries they are by necessity shared among the different 46 * helpers. 47 * 48 * To make this clear all the helper vtables are pulled together in this location here. 49 */ 50 51 struct drm_scanout_buffer; 52 struct drm_writeback_connector; 53 struct drm_writeback_job; 54 55 enum mode_set_atomic { 56 LEAVE_ATOMIC_MODE_SET, 57 ENTER_ATOMIC_MODE_SET, 58 }; 59 60 /** 61 * struct drm_crtc_helper_funcs - helper operations for CRTCs 62 * 63 * These hooks are used by the legacy CRTC helpers and the new atomic 64 * modesetting helpers. 65 */ 66 struct drm_crtc_helper_funcs { 67 /** 68 * @dpms: 69 * 70 * Callback to control power levels on the CRTC. If the mode passed in 71 * is unsupported, the provider must use the next lowest power level. 72 * This is used by the legacy CRTC helpers to implement DPMS 73 * functionality in drm_helper_connector_dpms(). 74 * 75 * This callback is also used to disable a CRTC by calling it with 76 * DRM_MODE_DPMS_OFF if the @disable hook isn't used. 77 * 78 * This callback is used by the legacy CRTC helpers. Atomic helpers 79 * also support using this hook for enabling and disabling a CRTC to 80 * facilitate transitions to atomic, but it is deprecated. Instead 81 * @atomic_enable and @atomic_disable should be used. 82 */ 83 void (*dpms)(struct drm_crtc *crtc, int mode); 84 85 /** 86 * @prepare: 87 * 88 * This callback should prepare the CRTC for a subsequent modeset, which 89 * in practice means the driver should disable the CRTC if it is 90 * running. Most drivers ended up implementing this by calling their 91 * @dpms hook with DRM_MODE_DPMS_OFF. 92 * 93 * This callback is used by the legacy CRTC helpers. Atomic helpers 94 * also support using this hook for disabling a CRTC to facilitate 95 * transitions to atomic, but it is deprecated. Instead @atomic_disable 96 * should be used. 97 */ 98 void (*prepare)(struct drm_crtc *crtc); 99 100 /** 101 * @commit: 102 * 103 * This callback should commit the new mode on the CRTC after a modeset, 104 * which in practice means the driver should enable the CRTC. Most 105 * drivers ended up implementing this by calling their @dpms hook with 106 * DRM_MODE_DPMS_ON. 107 * 108 * This callback is used by the legacy CRTC helpers. Atomic helpers 109 * also support using this hook for enabling a CRTC to facilitate 110 * transitions to atomic, but it is deprecated. Instead @atomic_enable 111 * should be used. 112 */ 113 void (*commit)(struct drm_crtc *crtc); 114 115 /** 116 * @mode_valid: 117 * 118 * This callback is used to check if a specific mode is valid in this 119 * crtc. This should be implemented if the crtc has some sort of 120 * restriction in the modes it can display. For example, a given crtc 121 * may be responsible to set a clock value. If the clock can not 122 * produce all the values for the available modes then this callback 123 * can be used to restrict the number of modes to only the ones that 124 * can be displayed. 125 * 126 * This hook is used by the probe helpers to filter the mode list in 127 * drm_helper_probe_single_connector_modes(), and it is used by the 128 * atomic helpers to validate modes supplied by userspace in 129 * drm_atomic_helper_check_modeset(). 130 * 131 * This function is optional. 132 * 133 * NOTE: 134 * 135 * Since this function is both called from the check phase of an atomic 136 * commit, and the mode validation in the probe paths it is not allowed 137 * to look at anything else but the passed-in mode, and validate it 138 * against configuration-invariant hardware constraints. Any further 139 * limits which depend upon the configuration can only be checked in 140 * @mode_fixup or @atomic_check. 141 * 142 * RETURNS: 143 * 144 * drm_mode_status Enum 145 */ 146 enum drm_mode_status (*mode_valid)(struct drm_crtc *crtc, 147 const struct drm_display_mode *mode); 148 149 /** 150 * @mode_fixup: 151 * 152 * This callback is used to validate a mode. The parameter mode is the 153 * display mode that userspace requested, adjusted_mode is the mode the 154 * encoders need to be fed with. Note that this is the inverse semantics 155 * of the meaning for the &drm_encoder and &drm_bridge_funcs.mode_fixup 156 * vfunc. If the CRTC cannot support the requested conversion from mode 157 * to adjusted_mode it should reject the modeset. See also 158 * &drm_crtc_state.adjusted_mode for more details. 159 * 160 * This function is used by both legacy CRTC helpers and atomic helpers. 161 * With atomic helpers it is optional. 162 * 163 * NOTE: 164 * 165 * This function is called in the check phase of atomic modesets, which 166 * can be aborted for any reason (including on userspace's request to 167 * just check whether a configuration would be possible). Atomic drivers 168 * MUST NOT touch any persistent state (hardware or software) or data 169 * structures except the passed in adjusted_mode parameter. 170 * 171 * This is in contrast to the legacy CRTC helpers where this was 172 * allowed. 173 * 174 * Atomic drivers which need to inspect and adjust more state should 175 * instead use the @atomic_check callback, but note that they're not 176 * perfectly equivalent: @mode_valid is called from 177 * drm_atomic_helper_check_modeset(), but @atomic_check is called from 178 * drm_atomic_helper_check_planes(), because originally it was meant for 179 * plane update checks only. 180 * 181 * Also beware that userspace can request its own custom modes, neither 182 * core nor helpers filter modes to the list of probe modes reported by 183 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure 184 * that modes are filtered consistently put any CRTC constraints and 185 * limits checks into @mode_valid. 186 * 187 * RETURNS: 188 * 189 * True if an acceptable configuration is possible, false if the modeset 190 * operation should be rejected. 191 */ 192 bool (*mode_fixup)(struct drm_crtc *crtc, 193 const struct drm_display_mode *mode, 194 struct drm_display_mode *adjusted_mode); 195 196 /** 197 * @mode_set: 198 * 199 * This callback is used by the legacy CRTC helpers to set a new mode, 200 * position and framebuffer. Since it ties the primary plane to every 201 * mode change it is incompatible with universal plane support. And 202 * since it can't update other planes it's incompatible with atomic 203 * modeset support. 204 * 205 * This callback is only used by CRTC helpers and deprecated. 206 * 207 * RETURNS: 208 * 209 * 0 on success or a negative error code on failure. 210 */ 211 int (*mode_set)(struct drm_crtc *crtc, struct drm_display_mode *mode, 212 struct drm_display_mode *adjusted_mode, int x, int y, 213 struct drm_framebuffer *old_fb); 214 215 /** 216 * @mode_set_nofb: 217 * 218 * This callback is used to update the display mode of a CRTC without 219 * changing anything of the primary plane configuration. This fits the 220 * requirement of atomic and hence is used by the atomic helpers. 221 * 222 * Note that the display pipe is completely off when this function is 223 * called. Atomic drivers which need hardware to be running before they 224 * program the new display mode (e.g. because they implement runtime PM) 225 * should not use this hook. This is because the helper library calls 226 * this hook only once per mode change and not every time the display 227 * pipeline is suspended using either DPMS or the new "ACTIVE" property. 228 * Which means register values set in this callback might get reset when 229 * the CRTC is suspended, but not restored. Such drivers should instead 230 * move all their CRTC setup into the @atomic_enable callback. 231 * 232 * This callback is optional. 233 */ 234 void (*mode_set_nofb)(struct drm_crtc *crtc); 235 236 /** 237 * @mode_set_base: 238 * 239 * This callback is used by the legacy CRTC helpers to set a new 240 * framebuffer and scanout position. It is optional and used as an 241 * optimized fast-path instead of a full mode set operation with all the 242 * resulting flickering. If it is not present 243 * drm_crtc_helper_set_config() will fall back to a full modeset, using 244 * the @mode_set callback. Since it can't update other planes it's 245 * incompatible with atomic modeset support. 246 * 247 * This callback is only used by the CRTC helpers and deprecated. 248 * 249 * RETURNS: 250 * 251 * 0 on success or a negative error code on failure. 252 */ 253 int (*mode_set_base)(struct drm_crtc *crtc, int x, int y, 254 struct drm_framebuffer *old_fb); 255 256 /** 257 * @mode_set_base_atomic: 258 * 259 * This callback is used by the fbdev helpers to set a new framebuffer 260 * and scanout without sleeping, i.e. from an atomic calling context. It 261 * is only used to implement kgdb support. 262 * 263 * This callback is optional and only needed for kgdb support in the fbdev 264 * helpers. 265 * 266 * RETURNS: 267 * 268 * 0 on success or a negative error code on failure. 269 */ 270 int (*mode_set_base_atomic)(struct drm_crtc *crtc, 271 struct drm_framebuffer *fb, int x, int y, 272 enum mode_set_atomic); 273 274 /** 275 * @disable: 276 * 277 * This callback should be used to disable the CRTC. With the atomic 278 * drivers it is called after all encoders connected to this CRTC have 279 * been shut off already using their own 280 * &drm_encoder_helper_funcs.disable hook. If that sequence is too 281 * simple drivers can just add their own hooks and call it from this 282 * CRTC callback here by looping over all encoders connected to it using 283 * for_each_encoder_on_crtc(). 284 * 285 * This hook is used both by legacy CRTC helpers and atomic helpers. 286 * Atomic drivers don't need to implement it if there's no need to 287 * disable anything at the CRTC level. To ensure that runtime PM 288 * handling (using either DPMS or the new "ACTIVE" property) works 289 * @disable must be the inverse of @atomic_enable for atomic drivers. 290 * Atomic drivers should consider to use @atomic_disable instead of 291 * this one. 292 * 293 * NOTE: 294 * 295 * With legacy CRTC helpers there's a big semantic difference between 296 * @disable and other hooks (like @prepare or @dpms) used to shut down a 297 * CRTC: @disable is only called when also logically disabling the 298 * display pipeline and needs to release any resources acquired in 299 * @mode_set (like shared PLLs, or again release pinned framebuffers). 300 * 301 * Therefore @disable must be the inverse of @mode_set plus @commit for 302 * drivers still using legacy CRTC helpers, which is different from the 303 * rules under atomic. 304 */ 305 void (*disable)(struct drm_crtc *crtc); 306 307 /** 308 * @atomic_check: 309 * 310 * Drivers should check plane-update related CRTC constraints in this 311 * hook. They can also check mode related limitations but need to be 312 * aware of the calling order, since this hook is used by 313 * drm_atomic_helper_check_planes() whereas the preparations needed to 314 * check output routing and the display mode is done in 315 * drm_atomic_helper_check_modeset(). Therefore drivers that want to 316 * check output routing and display mode constraints in this callback 317 * must ensure that drm_atomic_helper_check_modeset() has been called 318 * beforehand. This is calling order used by the default helper 319 * implementation in drm_atomic_helper_check(). 320 * 321 * When using drm_atomic_helper_check_planes() this hook is called 322 * after the &drm_plane_helper_funcs.atomic_check hook for planes, which 323 * allows drivers to assign shared resources requested by planes in this 324 * callback here. For more complicated dependencies the driver can call 325 * the provided check helpers multiple times until the computed state 326 * has a final configuration and everything has been checked. 327 * 328 * This function is also allowed to inspect any other object's state and 329 * can add more state objects to the atomic commit if needed. Care must 330 * be taken though to ensure that state check and compute functions for 331 * these added states are all called, and derived state in other objects 332 * all updated. Again the recommendation is to just call check helpers 333 * until a maximal configuration is reached. 334 * 335 * This callback is used by the atomic modeset helpers, but it is 336 * optional. 337 * 338 * NOTE: 339 * 340 * This function is called in the check phase of an atomic update. The 341 * driver is not allowed to change anything outside of the free-standing 342 * state object passed-in. 343 * 344 * Also beware that userspace can request its own custom modes, neither 345 * core nor helpers filter modes to the list of probe modes reported by 346 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure 347 * that modes are filtered consistently put any CRTC constraints and 348 * limits checks into @mode_valid. 349 * 350 * RETURNS: 351 * 352 * 0 on success, -EINVAL if the state or the transition can't be 353 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an 354 * attempt to obtain another state object ran into a &drm_modeset_lock 355 * deadlock. 356 */ 357 int (*atomic_check)(struct drm_crtc *crtc, 358 struct drm_atomic_state *state); 359 360 /** 361 * @atomic_begin: 362 * 363 * Drivers should prepare for an atomic update of multiple planes on 364 * a CRTC in this hook. Depending upon hardware this might be vblank 365 * evasion, blocking updates by setting bits or doing preparatory work 366 * for e.g. manual update display. 367 * 368 * This hook is called before any plane commit functions are called. 369 * 370 * Note that the power state of the display pipe when this function is 371 * called depends upon the exact helpers and calling sequence the driver 372 * has picked. See drm_atomic_helper_commit_planes() for a discussion of 373 * the tradeoffs and variants of plane commit helpers. 374 * 375 * This callback is used by the atomic modeset helpers, but it is 376 * optional. 377 */ 378 void (*atomic_begin)(struct drm_crtc *crtc, 379 struct drm_atomic_state *state); 380 /** 381 * @atomic_flush: 382 * 383 * Drivers should finalize an atomic update of multiple planes on 384 * a CRTC in this hook. Depending upon hardware this might include 385 * checking that vblank evasion was successful, unblocking updates by 386 * setting bits or setting the GO bit to flush out all updates. 387 * 388 * Simple hardware or hardware with special requirements can commit and 389 * flush out all updates for all planes from this hook and forgo all the 390 * other commit hooks for plane updates. 391 * 392 * This hook is called after any plane commit functions are called. 393 * 394 * Note that the power state of the display pipe when this function is 395 * called depends upon the exact helpers and calling sequence the driver 396 * has picked. See drm_atomic_helper_commit_planes() for a discussion of 397 * the tradeoffs and variants of plane commit helpers. 398 * 399 * This callback is used by the atomic modeset helpers, but it is 400 * optional. 401 */ 402 void (*atomic_flush)(struct drm_crtc *crtc, 403 struct drm_atomic_state *state); 404 405 /** 406 * @atomic_enable: 407 * 408 * This callback should be used to enable the CRTC. With the atomic 409 * drivers it is called before all encoders connected to this CRTC are 410 * enabled through the encoder's own &drm_encoder_helper_funcs.enable 411 * hook. If that sequence is too simple drivers can just add their own 412 * hooks and call it from this CRTC callback here by looping over all 413 * encoders connected to it using for_each_encoder_on_crtc(). 414 * 415 * This hook is used only by atomic helpers, for symmetry with 416 * @atomic_disable. Atomic drivers don't need to implement it if there's 417 * no need to enable anything at the CRTC level. To ensure that runtime 418 * PM handling (using either DPMS or the new "ACTIVE" property) works 419 * @atomic_enable must be the inverse of @atomic_disable for atomic 420 * drivers. 421 * 422 * This function is optional. 423 */ 424 void (*atomic_enable)(struct drm_crtc *crtc, 425 struct drm_atomic_state *state); 426 427 /** 428 * @atomic_disable: 429 * 430 * This callback should be used to disable the CRTC. With the atomic 431 * drivers it is called after all encoders connected to this CRTC have 432 * been shut off already using their own 433 * &drm_encoder_helper_funcs.disable hook. If that sequence is too 434 * simple drivers can just add their own hooks and call it from this 435 * CRTC callback here by looping over all encoders connected to it using 436 * for_each_encoder_on_crtc(). 437 * 438 * This hook is used only by atomic helpers. Atomic drivers don't 439 * need to implement it if there's no need to disable anything at the 440 * CRTC level. 441 * 442 * This function is optional. 443 */ 444 void (*atomic_disable)(struct drm_crtc *crtc, 445 struct drm_atomic_state *state); 446 447 /** 448 * @get_scanout_position: 449 * 450 * Called by vblank timestamping code. 451 * 452 * Returns the current display scanout position from a CRTC and an 453 * optional accurate ktime_get() timestamp of when the position was 454 * measured. Note that this is a helper callback which is only used 455 * if a driver uses drm_crtc_vblank_helper_get_vblank_timestamp() 456 * for the @drm_crtc_funcs.get_vblank_timestamp callback. 457 * 458 * Parameters: 459 * 460 * crtc: 461 * The CRTC. 462 * in_vblank_irq: 463 * True when called from drm_crtc_handle_vblank(). Some drivers 464 * need to apply some workarounds for gpu-specific vblank irq 465 * quirks if the flag is set. 466 * vpos: 467 * Target location for current vertical scanout position. 468 * hpos: 469 * Target location for current horizontal scanout position. 470 * stime: 471 * Target location for timestamp taken immediately before 472 * scanout position query. Can be NULL to skip timestamp. 473 * etime: 474 * Target location for timestamp taken immediately after 475 * scanout position query. Can be NULL to skip timestamp. 476 * mode: 477 * Current display timings. 478 * 479 * Returns vpos as a positive number while in active scanout area. 480 * Returns vpos as a negative number inside vblank, counting the number 481 * of scanlines to go until end of vblank, e.g., -1 means "one scanline 482 * until start of active scanout / end of vblank." 483 * 484 * Returns: 485 * 486 * True on success, false if a reliable scanout position counter could 487 * not be read out. 488 */ 489 bool (*get_scanout_position)(struct drm_crtc *crtc, 490 bool in_vblank_irq, int *vpos, int *hpos, 491 ktime_t *stime, ktime_t *etime, 492 const struct drm_display_mode *mode); 493 }; 494 495 /** 496 * drm_crtc_helper_add - sets the helper vtable for a crtc 497 * @crtc: DRM CRTC 498 * @funcs: helper vtable to set for @crtc 499 */ drm_crtc_helper_add(struct drm_crtc * crtc,const struct drm_crtc_helper_funcs * funcs)500 static inline void drm_crtc_helper_add(struct drm_crtc *crtc, 501 const struct drm_crtc_helper_funcs *funcs) 502 { 503 crtc->helper_private = funcs; 504 } 505 506 /** 507 * struct drm_encoder_helper_funcs - helper operations for encoders 508 * 509 * These hooks are used by the legacy CRTC helpers and the new atomic 510 * modesetting helpers. 511 */ 512 struct drm_encoder_helper_funcs { 513 /** 514 * @dpms: 515 * 516 * Callback to control power levels on the encoder. If the mode passed in 517 * is unsupported, the provider must use the next lowest power level. 518 * This is used by the legacy encoder helpers to implement DPMS 519 * functionality in drm_helper_connector_dpms(). 520 * 521 * This callback is also used to disable an encoder by calling it with 522 * DRM_MODE_DPMS_OFF if the @disable hook isn't used. 523 * 524 * This callback is used by the legacy CRTC helpers. Atomic helpers 525 * also support using this hook for enabling and disabling an encoder to 526 * facilitate transitions to atomic, but it is deprecated. Instead 527 * @enable and @disable should be used. 528 */ 529 void (*dpms)(struct drm_encoder *encoder, int mode); 530 531 /** 532 * @mode_valid: 533 * 534 * This callback is used to check if a specific mode is valid in this 535 * encoder. This should be implemented if the encoder has some sort 536 * of restriction in the modes it can display. For example, a given 537 * encoder may be responsible to set a clock value. If the clock can 538 * not produce all the values for the available modes then this callback 539 * can be used to restrict the number of modes to only the ones that 540 * can be displayed. 541 * 542 * This hook is used by the probe helpers to filter the mode list in 543 * drm_helper_probe_single_connector_modes(), and it is used by the 544 * atomic helpers to validate modes supplied by userspace in 545 * drm_atomic_helper_check_modeset(). 546 * 547 * This function is optional. 548 * 549 * NOTE: 550 * 551 * Since this function is both called from the check phase of an atomic 552 * commit, and the mode validation in the probe paths it is not allowed 553 * to look at anything else but the passed-in mode, and validate it 554 * against configuration-invariant hardware constraints. Any further 555 * limits which depend upon the configuration can only be checked in 556 * @mode_fixup or @atomic_check. 557 * 558 * RETURNS: 559 * 560 * drm_mode_status Enum 561 */ 562 enum drm_mode_status (*mode_valid)(struct drm_encoder *crtc, 563 const struct drm_display_mode *mode); 564 565 /** 566 * @mode_fixup: 567 * 568 * This callback is used to validate and adjust a mode. The parameter 569 * mode is the display mode that should be fed to the next element in 570 * the display chain, either the final &drm_connector or a &drm_bridge. 571 * The parameter adjusted_mode is the input mode the encoder requires. It 572 * can be modified by this callback and does not need to match mode. See 573 * also &drm_crtc_state.adjusted_mode for more details. 574 * 575 * This function is used by both legacy CRTC helpers and atomic helpers. 576 * This hook is optional. 577 * 578 * NOTE: 579 * 580 * This function is called in the check phase of atomic modesets, which 581 * can be aborted for any reason (including on userspace's request to 582 * just check whether a configuration would be possible). Atomic drivers 583 * MUST NOT touch any persistent state (hardware or software) or data 584 * structures except the passed in adjusted_mode parameter. 585 * 586 * This is in contrast to the legacy CRTC helpers where this was 587 * allowed. 588 * 589 * Atomic drivers which need to inspect and adjust more state should 590 * instead use the @atomic_check callback. If @atomic_check is used, 591 * this hook isn't called since @atomic_check allows a strict superset 592 * of the functionality of @mode_fixup. 593 * 594 * Also beware that userspace can request its own custom modes, neither 595 * core nor helpers filter modes to the list of probe modes reported by 596 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure 597 * that modes are filtered consistently put any encoder constraints and 598 * limits checks into @mode_valid. 599 * 600 * RETURNS: 601 * 602 * True if an acceptable configuration is possible, false if the modeset 603 * operation should be rejected. 604 */ 605 bool (*mode_fixup)(struct drm_encoder *encoder, 606 const struct drm_display_mode *mode, 607 struct drm_display_mode *adjusted_mode); 608 609 /** 610 * @prepare: 611 * 612 * This callback should prepare the encoder for a subsequent modeset, 613 * which in practice means the driver should disable the encoder if it 614 * is running. Most drivers ended up implementing this by calling their 615 * @dpms hook with DRM_MODE_DPMS_OFF. 616 * 617 * This callback is used by the legacy CRTC helpers. Atomic helpers 618 * also support using this hook for disabling an encoder to facilitate 619 * transitions to atomic, but it is deprecated. Instead @disable should 620 * be used. 621 */ 622 void (*prepare)(struct drm_encoder *encoder); 623 624 /** 625 * @commit: 626 * 627 * This callback should commit the new mode on the encoder after a modeset, 628 * which in practice means the driver should enable the encoder. Most 629 * drivers ended up implementing this by calling their @dpms hook with 630 * DRM_MODE_DPMS_ON. 631 * 632 * This callback is used by the legacy CRTC helpers. Atomic helpers 633 * also support using this hook for enabling an encoder to facilitate 634 * transitions to atomic, but it is deprecated. Instead @enable should 635 * be used. 636 */ 637 void (*commit)(struct drm_encoder *encoder); 638 639 /** 640 * @mode_set: 641 * 642 * This callback is used to update the display mode of an encoder. 643 * 644 * Note that the display pipe is completely off when this function is 645 * called. Drivers which need hardware to be running before they program 646 * the new display mode (because they implement runtime PM) should not 647 * use this hook, because the helper library calls it only once and not 648 * every time the display pipeline is suspend using either DPMS or the 649 * new "ACTIVE" property. Such drivers should instead move all their 650 * encoder setup into the @enable callback. 651 * 652 * This callback is used both by the legacy CRTC helpers and the atomic 653 * modeset helpers. It is optional in the atomic helpers. 654 * 655 * NOTE: 656 * 657 * If the driver uses the atomic modeset helpers and needs to inspect 658 * the connector state or connector display info during mode setting, 659 * @atomic_mode_set can be used instead. 660 */ 661 void (*mode_set)(struct drm_encoder *encoder, 662 struct drm_display_mode *mode, 663 struct drm_display_mode *adjusted_mode); 664 665 /** 666 * @atomic_mode_set: 667 * 668 * This callback is used to update the display mode of an encoder. 669 * 670 * Note that the display pipe is completely off when this function is 671 * called. Drivers which need hardware to be running before they program 672 * the new display mode (because they implement runtime PM) should not 673 * use this hook, because the helper library calls it only once and not 674 * every time the display pipeline is suspended using either DPMS or the 675 * new "ACTIVE" property. Such drivers should instead move all their 676 * encoder setup into the @enable callback. 677 * 678 * This callback is used by the atomic modeset helpers in place of the 679 * @mode_set callback, if set by the driver. It is optional and should 680 * be used instead of @mode_set if the driver needs to inspect the 681 * connector state or display info, since there is no direct way to 682 * go from the encoder to the current connector. 683 */ 684 void (*atomic_mode_set)(struct drm_encoder *encoder, 685 struct drm_crtc_state *crtc_state, 686 struct drm_connector_state *conn_state); 687 688 /** 689 * @detect: 690 * 691 * This callback can be used by drivers who want to do detection on the 692 * encoder object instead of in connector functions. 693 * 694 * It is not used by any helper and therefore has purely driver-specific 695 * semantics. New drivers shouldn't use this and instead just implement 696 * their own private callbacks. 697 * 698 * FIXME: 699 * 700 * This should just be converted into a pile of driver vfuncs. 701 * Currently radeon, amdgpu and nouveau are using it. 702 */ 703 enum drm_connector_status (*detect)(struct drm_encoder *encoder, 704 struct drm_connector *connector); 705 706 /** 707 * @atomic_disable: 708 * 709 * This callback should be used to disable the encoder. With the atomic 710 * drivers it is called before this encoder's CRTC has been shut off 711 * using their own &drm_crtc_helper_funcs.atomic_disable hook. If that 712 * sequence is too simple drivers can just add their own driver private 713 * encoder hooks and call them from CRTC's callback by looping over all 714 * encoders connected to it using for_each_encoder_on_crtc(). 715 * 716 * This callback is a variant of @disable that provides the atomic state 717 * to the driver. If @atomic_disable is implemented, @disable is not 718 * called by the helpers. 719 * 720 * This hook is only used by atomic helpers. Atomic drivers don't need 721 * to implement it if there's no need to disable anything at the encoder 722 * level. To ensure that runtime PM handling (using either DPMS or the 723 * new "ACTIVE" property) works @atomic_disable must be the inverse of 724 * @atomic_enable. 725 */ 726 void (*atomic_disable)(struct drm_encoder *encoder, 727 struct drm_atomic_state *state); 728 729 /** 730 * @atomic_enable: 731 * 732 * This callback should be used to enable the encoder. It is called 733 * after this encoder's CRTC has been enabled using their own 734 * &drm_crtc_helper_funcs.atomic_enable hook. If that sequence is 735 * too simple drivers can just add their own driver private encoder 736 * hooks and call them from CRTC's callback by looping over all encoders 737 * connected to it using for_each_encoder_on_crtc(). 738 * 739 * This callback is a variant of @enable that provides the atomic state 740 * to the driver. If @atomic_enable is implemented, @enable is not 741 * called by the helpers. 742 * 743 * This hook is only used by atomic helpers, it is the opposite of 744 * @atomic_disable. Atomic drivers don't need to implement it if there's 745 * no need to enable anything at the encoder level. To ensure that 746 * runtime PM handling works @atomic_enable must be the inverse of 747 * @atomic_disable. 748 */ 749 void (*atomic_enable)(struct drm_encoder *encoder, 750 struct drm_atomic_state *state); 751 752 /** 753 * @disable: 754 * 755 * This callback should be used to disable the encoder. With the atomic 756 * drivers it is called before this encoder's CRTC has been shut off 757 * using their own &drm_crtc_helper_funcs.disable hook. If that 758 * sequence is too simple drivers can just add their own driver private 759 * encoder hooks and call them from CRTC's callback by looping over all 760 * encoders connected to it using for_each_encoder_on_crtc(). 761 * 762 * This hook is used both by legacy CRTC helpers and atomic helpers. 763 * Atomic drivers don't need to implement it if there's no need to 764 * disable anything at the encoder level. To ensure that runtime PM 765 * handling (using either DPMS or the new "ACTIVE" property) works 766 * @disable must be the inverse of @enable for atomic drivers. 767 * 768 * For atomic drivers also consider @atomic_disable and save yourself 769 * from having to read the NOTE below! 770 * 771 * NOTE: 772 * 773 * With legacy CRTC helpers there's a big semantic difference between 774 * @disable and other hooks (like @prepare or @dpms) used to shut down a 775 * encoder: @disable is only called when also logically disabling the 776 * display pipeline and needs to release any resources acquired in 777 * @mode_set (like shared PLLs, or again release pinned framebuffers). 778 * 779 * Therefore @disable must be the inverse of @mode_set plus @commit for 780 * drivers still using legacy CRTC helpers, which is different from the 781 * rules under atomic. 782 */ 783 void (*disable)(struct drm_encoder *encoder); 784 785 /** 786 * @enable: 787 * 788 * This callback should be used to enable the encoder. With the atomic 789 * drivers it is called after this encoder's CRTC has been enabled using 790 * their own &drm_crtc_helper_funcs.enable hook. If that sequence is 791 * too simple drivers can just add their own driver private encoder 792 * hooks and call them from CRTC's callback by looping over all encoders 793 * connected to it using for_each_encoder_on_crtc(). 794 * 795 * This hook is only used by atomic helpers, it is the opposite of 796 * @disable. Atomic drivers don't need to implement it if there's no 797 * need to enable anything at the encoder level. To ensure that 798 * runtime PM handling (using either DPMS or the new "ACTIVE" property) 799 * works @enable must be the inverse of @disable for atomic drivers. 800 */ 801 void (*enable)(struct drm_encoder *encoder); 802 803 /** 804 * @atomic_check: 805 * 806 * This callback is used to validate encoder state for atomic drivers. 807 * Since the encoder is the object connecting the CRTC and connector it 808 * gets passed both states, to be able to validate interactions and 809 * update the CRTC to match what the encoder needs for the requested 810 * connector. 811 * 812 * Since this provides a strict superset of the functionality of 813 * @mode_fixup (the requested and adjusted modes are both available 814 * through the passed in &struct drm_crtc_state) @mode_fixup is not 815 * called when @atomic_check is implemented. 816 * 817 * This function is used by the atomic helpers, but it is optional. 818 * 819 * NOTE: 820 * 821 * This function is called in the check phase of an atomic update. The 822 * driver is not allowed to change anything outside of the free-standing 823 * state objects passed-in or assembled in the overall &drm_atomic_state 824 * update tracking structure. 825 * 826 * Also beware that userspace can request its own custom modes, neither 827 * core nor helpers filter modes to the list of probe modes reported by 828 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure 829 * that modes are filtered consistently put any encoder constraints and 830 * limits checks into @mode_valid. 831 * 832 * RETURNS: 833 * 834 * 0 on success, -EINVAL if the state or the transition can't be 835 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an 836 * attempt to obtain another state object ran into a &drm_modeset_lock 837 * deadlock. 838 */ 839 int (*atomic_check)(struct drm_encoder *encoder, 840 struct drm_crtc_state *crtc_state, 841 struct drm_connector_state *conn_state); 842 }; 843 844 /** 845 * drm_encoder_helper_add - sets the helper vtable for an encoder 846 * @encoder: DRM encoder 847 * @funcs: helper vtable to set for @encoder 848 */ drm_encoder_helper_add(struct drm_encoder * encoder,const struct drm_encoder_helper_funcs * funcs)849 static inline void drm_encoder_helper_add(struct drm_encoder *encoder, 850 const struct drm_encoder_helper_funcs *funcs) 851 { 852 encoder->helper_private = funcs; 853 } 854 855 /** 856 * struct drm_connector_helper_funcs - helper operations for connectors 857 * 858 * These functions are used by the atomic and legacy modeset helpers and by the 859 * probe helpers. 860 */ 861 struct drm_connector_helper_funcs { 862 /** 863 * @get_modes: 864 * 865 * This function should fill in all modes currently valid for the sink 866 * into the &drm_connector.probed_modes list. It should also update the 867 * EDID property by calling drm_connector_update_edid_property(). 868 * 869 * The usual way to implement this is to cache the EDID retrieved in the 870 * probe callback somewhere in the driver-private connector structure. 871 * In this function drivers then parse the modes in the EDID and add 872 * them by calling drm_add_edid_modes(). But connectors that drive a 873 * fixed panel can also manually add specific modes using 874 * drm_mode_probed_add(). Drivers which manually add modes should also 875 * make sure that the &drm_connector.display_info, 876 * &drm_connector.width_mm and &drm_connector.height_mm fields are 877 * filled in. 878 * 879 * Note that the caller function will automatically add standard VESA 880 * DMT modes up to 1024x768 if the .get_modes() helper operation returns 881 * no mode and if the connector status is connector_status_connected or 882 * connector_status_unknown. There is no need to call 883 * drm_add_modes_noedid() manually in that case. 884 * 885 * Virtual drivers that just want some standard VESA mode with a given 886 * resolution can call drm_add_modes_noedid(), and mark the preferred 887 * one using drm_set_preferred_mode(). 888 * 889 * This function is only called after the @detect hook has indicated 890 * that a sink is connected and when the EDID isn't overridden through 891 * sysfs or the kernel commandline. 892 * 893 * This callback is used by the probe helpers in e.g. 894 * drm_helper_probe_single_connector_modes(). 895 * 896 * To avoid races with concurrent connector state updates, the helper 897 * libraries always call this with the &drm_mode_config.connection_mutex 898 * held. Because of this it's safe to inspect &drm_connector->state. 899 * 900 * RETURNS: 901 * 902 * The number of modes added by calling drm_mode_probed_add(). Return 0 903 * on failures (no modes) instead of negative error codes. 904 */ 905 int (*get_modes)(struct drm_connector *connector); 906 907 /** 908 * @detect_ctx: 909 * 910 * Check to see if anything is attached to the connector. The parameter 911 * force is set to false whilst polling, true when checking the 912 * connector due to a user request. force can be used by the driver to 913 * avoid expensive, destructive operations during automated probing. 914 * 915 * This callback is optional, if not implemented the connector will be 916 * considered as always being attached. 917 * 918 * This is the atomic version of &drm_connector_funcs.detect. 919 * 920 * To avoid races against concurrent connector state updates, the 921 * helper libraries always call this with ctx set to a valid context, 922 * and &drm_mode_config.connection_mutex will always be locked with 923 * the ctx parameter set to this ctx. This allows taking additional 924 * locks as required. 925 * 926 * RETURNS: 927 * 928 * &drm_connector_status indicating the connector's status, 929 * or the error code returned by drm_modeset_lock(), -EDEADLK. 930 */ 931 int (*detect_ctx)(struct drm_connector *connector, 932 struct drm_modeset_acquire_ctx *ctx, 933 bool force); 934 935 /** 936 * @mode_valid: 937 * 938 * Callback to validate a mode for a connector, irrespective of the 939 * specific display configuration. 940 * 941 * This callback is used by the probe helpers to filter the mode list 942 * (which is usually derived from the EDID data block from the sink). 943 * See e.g. drm_helper_probe_single_connector_modes(). 944 * 945 * This function is optional. 946 * 947 * NOTE: 948 * 949 * This only filters the mode list supplied to userspace in the 950 * GETCONNECTOR IOCTL. Compared to &drm_encoder_helper_funcs.mode_valid, 951 * &drm_crtc_helper_funcs.mode_valid and &drm_bridge_funcs.mode_valid, 952 * which are also called by the atomic helpers from 953 * drm_atomic_helper_check_modeset(). This allows userspace to force and 954 * ignore sink constraint (like the pixel clock limits in the screen's 955 * EDID), which is useful for e.g. testing, or working around a broken 956 * EDID. Any source hardware constraint (which always need to be 957 * enforced) therefore should be checked in one of the above callbacks, 958 * and not this one here. 959 * 960 * To avoid races with concurrent connector state updates, the helper 961 * libraries always call this with the &drm_mode_config.connection_mutex 962 * held. Because of this it's safe to inspect &drm_connector->state. 963 * 964 * RETURNS: 965 * 966 * Either &drm_mode_status.MODE_OK or one of the failure reasons in &enum 967 * drm_mode_status. 968 */ 969 enum drm_mode_status (*mode_valid)(struct drm_connector *connector, 970 struct drm_display_mode *mode); 971 972 /** 973 * @mode_valid_ctx: 974 * 975 * Callback to validate a mode for a connector, irrespective of the 976 * specific display configuration. 977 * 978 * This callback is used by the probe helpers to filter the mode list 979 * (which is usually derived from the EDID data block from the sink). 980 * See e.g. drm_helper_probe_single_connector_modes(). 981 * 982 * This function is optional, and is the atomic version of 983 * &drm_connector_helper_funcs.mode_valid. 984 * 985 * To allow for accessing the atomic state of modesetting objects, the 986 * helper libraries always call this with ctx set to a valid context, 987 * and &drm_mode_config.connection_mutex will always be locked with 988 * the ctx parameter set to @ctx. This allows for taking additional 989 * locks as required. 990 * 991 * Even though additional locks may be acquired, this callback is 992 * still expected not to take any constraints into account which would 993 * be influenced by the currently set display state - such constraints 994 * should be handled in the driver's atomic check. For example, if a 995 * connector shares display bandwidth with other connectors then it 996 * would be ok to validate the minimum bandwidth requirement of a mode 997 * against the maximum possible bandwidth of the connector. But it 998 * wouldn't be ok to take the current bandwidth usage of other 999 * connectors into account, as this would change depending on the 1000 * display state. 1001 * 1002 * Returns: 1003 * 0 if &drm_connector_helper_funcs.mode_valid_ctx succeeded and wrote 1004 * the &enum drm_mode_status value to @status, or a negative error 1005 * code otherwise. 1006 * 1007 */ 1008 int (*mode_valid_ctx)(struct drm_connector *connector, 1009 struct drm_display_mode *mode, 1010 struct drm_modeset_acquire_ctx *ctx, 1011 enum drm_mode_status *status); 1012 1013 /** 1014 * @best_encoder: 1015 * 1016 * This function should select the best encoder for the given connector. 1017 * 1018 * This function is used by both the atomic helpers (in the 1019 * drm_atomic_helper_check_modeset() function) and in the legacy CRTC 1020 * helpers. 1021 * 1022 * NOTE: 1023 * 1024 * In atomic drivers this function is called in the check phase of an 1025 * atomic update. The driver is not allowed to change or inspect 1026 * anything outside of arguments passed-in. Atomic drivers which need to 1027 * inspect dynamic configuration state should instead use 1028 * @atomic_best_encoder. 1029 * 1030 * You can leave this function to NULL if the connector is only 1031 * attached to a single encoder. In this case, the core will call 1032 * drm_connector_get_single_encoder() for you. 1033 * 1034 * RETURNS: 1035 * 1036 * Encoder that should be used for the given connector and connector 1037 * state, or NULL if no suitable encoder exists. Note that the helpers 1038 * will ensure that encoders aren't used twice, drivers should not check 1039 * for this. 1040 */ 1041 struct drm_encoder *(*best_encoder)(struct drm_connector *connector); 1042 1043 /** 1044 * @atomic_best_encoder: 1045 * 1046 * This is the atomic version of @best_encoder for atomic drivers which 1047 * need to select the best encoder depending upon the desired 1048 * configuration and can't select it statically. 1049 * 1050 * This function is used by drm_atomic_helper_check_modeset(). 1051 * If it is not implemented, the core will fallback to @best_encoder 1052 * (or drm_connector_get_single_encoder() if @best_encoder is NULL). 1053 * 1054 * NOTE: 1055 * 1056 * This function is called in the check phase of an atomic update. The 1057 * driver is not allowed to change anything outside of the 1058 * &drm_atomic_state update tracking structure passed in. 1059 * 1060 * RETURNS: 1061 * 1062 * Encoder that should be used for the given connector and connector 1063 * state, or NULL if no suitable encoder exists. Note that the helpers 1064 * will ensure that encoders aren't used twice, drivers should not check 1065 * for this. 1066 */ 1067 struct drm_encoder *(*atomic_best_encoder)(struct drm_connector *connector, 1068 struct drm_atomic_state *state); 1069 1070 /** 1071 * @atomic_check: 1072 * 1073 * This hook is used to validate connector state. This function is 1074 * called from &drm_atomic_helper_check_modeset, and is called when 1075 * a connector property is set, or a modeset on the crtc is forced. 1076 * 1077 * Because &drm_atomic_helper_check_modeset may be called multiple times, 1078 * this function should handle being called multiple times as well. 1079 * 1080 * This function is also allowed to inspect any other object's state and 1081 * can add more state objects to the atomic commit if needed. Care must 1082 * be taken though to ensure that state check and compute functions for 1083 * these added states are all called, and derived state in other objects 1084 * all updated. Again the recommendation is to just call check helpers 1085 * until a maximal configuration is reached. 1086 * 1087 * NOTE: 1088 * 1089 * This function is called in the check phase of an atomic update. The 1090 * driver is not allowed to change anything outside of the free-standing 1091 * state objects passed-in or assembled in the overall &drm_atomic_state 1092 * update tracking structure. 1093 * 1094 * RETURNS: 1095 * 1096 * 0 on success, -EINVAL if the state or the transition can't be 1097 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an 1098 * attempt to obtain another state object ran into a &drm_modeset_lock 1099 * deadlock. 1100 */ 1101 int (*atomic_check)(struct drm_connector *connector, 1102 struct drm_atomic_state *state); 1103 1104 /** 1105 * @atomic_commit: 1106 * 1107 * This hook is to be used by drivers implementing writeback connectors 1108 * that need a point when to commit the writeback job to the hardware. 1109 * The writeback_job to commit is available in the new connector state, 1110 * in &drm_connector_state.writeback_job. 1111 * 1112 * This hook is optional. 1113 * 1114 * This callback is used by the atomic modeset helpers. 1115 */ 1116 void (*atomic_commit)(struct drm_connector *connector, 1117 struct drm_atomic_state *state); 1118 1119 /** 1120 * @prepare_writeback_job: 1121 * 1122 * As writeback jobs contain a framebuffer, drivers may need to 1123 * prepare and clean them up the same way they can prepare and 1124 * clean up framebuffers for planes. This optional connector operation 1125 * is used to support the preparation of writeback jobs. The job 1126 * prepare operation is called from drm_atomic_helper_prepare_planes() 1127 * for struct &drm_writeback_connector connectors only. 1128 * 1129 * This operation is optional. 1130 * 1131 * This callback is used by the atomic modeset helpers. 1132 */ 1133 int (*prepare_writeback_job)(struct drm_writeback_connector *connector, 1134 struct drm_writeback_job *job); 1135 /** 1136 * @cleanup_writeback_job: 1137 * 1138 * This optional connector operation is used to support the 1139 * cleanup of writeback jobs. The job cleanup operation is called 1140 * from the existing drm_writeback_cleanup_job() function, invoked 1141 * both when destroying the job as part of an aborted commit, or when 1142 * the job completes. 1143 * 1144 * This operation is optional. 1145 * 1146 * This callback is used by the atomic modeset helpers. 1147 */ 1148 void (*cleanup_writeback_job)(struct drm_writeback_connector *connector, 1149 struct drm_writeback_job *job); 1150 1151 /** 1152 * @enable_hpd: 1153 * 1154 * Enable hot-plug detection for the connector. 1155 * 1156 * This operation is optional. 1157 * 1158 * This callback is used by the drm_kms_helper_poll_enable() helpers. 1159 * 1160 * This operation does not need to perform any hpd state tracking as 1161 * the DRM core handles that maintenance and ensures the calls to enable 1162 * and disable hpd are balanced. 1163 * 1164 */ 1165 void (*enable_hpd)(struct drm_connector *connector); 1166 1167 /** 1168 * @disable_hpd: 1169 * 1170 * Disable hot-plug detection for the connector. 1171 * 1172 * This operation is optional. 1173 * 1174 * This callback is used by the drm_kms_helper_poll_disable() helpers. 1175 * 1176 * This operation does not need to perform any hpd state tracking as 1177 * the DRM core handles that maintenance and ensures the calls to enable 1178 * and disable hpd are balanced. 1179 * 1180 */ 1181 void (*disable_hpd)(struct drm_connector *connector); 1182 }; 1183 1184 /** 1185 * drm_connector_helper_add - sets the helper vtable for a connector 1186 * @connector: DRM connector 1187 * @funcs: helper vtable to set for @connector 1188 */ drm_connector_helper_add(struct drm_connector * connector,const struct drm_connector_helper_funcs * funcs)1189 static inline void drm_connector_helper_add(struct drm_connector *connector, 1190 const struct drm_connector_helper_funcs *funcs) 1191 { 1192 connector->helper_private = funcs; 1193 } 1194 1195 /** 1196 * struct drm_plane_helper_funcs - helper operations for planes 1197 * 1198 * These functions are used by the atomic helpers. 1199 */ 1200 struct drm_plane_helper_funcs { 1201 /** 1202 * @prepare_fb: 1203 * 1204 * This hook is to prepare a framebuffer for scanout by e.g. pinning 1205 * its backing storage or relocating it into a contiguous block of 1206 * VRAM. Other possible preparatory work includes flushing caches. 1207 * 1208 * This function must not block for outstanding rendering, since it is 1209 * called in the context of the atomic IOCTL even for async commits to 1210 * be able to return any errors to userspace. Instead the recommended 1211 * way is to fill out the &drm_plane_state.fence of the passed-in 1212 * &drm_plane_state. If the driver doesn't support native fences then 1213 * equivalent functionality should be implemented through private 1214 * members in the plane structure. 1215 * 1216 * For GEM drivers who neither have a @prepare_fb nor @cleanup_fb hook 1217 * set drm_gem_plane_helper_prepare_fb() is called automatically to 1218 * implement this. Other drivers which need additional plane processing 1219 * can call drm_gem_plane_helper_prepare_fb() from their @prepare_fb 1220 * hook. 1221 * 1222 * The resources acquired in @prepare_fb persist after the end of 1223 * the atomic commit. Resources that can be release at the commit's end 1224 * should be acquired in @begin_fb_access and released in @end_fb_access. 1225 * For example, a GEM buffer's pin operation belongs into @prepare_fb to 1226 * keep the buffer pinned after the commit. But a vmap operation for 1227 * shadow-plane helpers belongs into @begin_fb_access, so that atomic 1228 * helpers remove the mapping at the end of the commit. 1229 * 1230 * The helpers will call @cleanup_fb with matching arguments for every 1231 * successful call to this hook. 1232 * 1233 * This callback is used by the atomic modeset helpers, but it is 1234 * optional. See @begin_fb_access for preparing per-commit resources. 1235 * 1236 * RETURNS: 1237 * 1238 * 0 on success or one of the following negative error codes allowed by 1239 * the &drm_mode_config_funcs.atomic_commit vfunc. When using helpers 1240 * this callback is the only one which can fail an atomic commit, 1241 * everything else must complete successfully. 1242 */ 1243 int (*prepare_fb)(struct drm_plane *plane, 1244 struct drm_plane_state *new_state); 1245 /** 1246 * @cleanup_fb: 1247 * 1248 * This hook is called to clean up any resources allocated for the given 1249 * framebuffer and plane configuration in @prepare_fb. 1250 * 1251 * This callback is used by the atomic modeset helpers, but it is 1252 * optional. 1253 */ 1254 void (*cleanup_fb)(struct drm_plane *plane, 1255 struct drm_plane_state *old_state); 1256 1257 /** 1258 * @begin_fb_access: 1259 * 1260 * This hook prepares the plane for access during an atomic commit. 1261 * In contrast to @prepare_fb, resources acquired in @begin_fb_access, 1262 * are released at the end of the atomic commit in @end_fb_access. 1263 * 1264 * For example, with shadow-plane helpers, the GEM buffer's vmap 1265 * operation belongs into @begin_fb_access, so that the buffer's 1266 * memory will be unmapped at the end of the commit in @end_fb_access. 1267 * But a GEM buffer's pin operation belongs into @prepare_fb 1268 * to keep the buffer pinned after the commit. 1269 * 1270 * The callback is used by the atomic modeset helpers, but it is optional. 1271 * See @end_fb_cleanup for undoing the effects of @begin_fb_access and 1272 * @prepare_fb for acquiring resources until the next pageflip. 1273 * 1274 * Returns: 1275 * 0 on success, or a negative errno code otherwise. 1276 */ 1277 int (*begin_fb_access)(struct drm_plane *plane, struct drm_plane_state *new_plane_state); 1278 1279 /** 1280 * @end_fb_access: 1281 * 1282 * This hook cleans up resources allocated by @begin_fb_access. It it called 1283 * at the end of a commit for the new plane state. 1284 */ 1285 void (*end_fb_access)(struct drm_plane *plane, struct drm_plane_state *new_plane_state); 1286 1287 /** 1288 * @atomic_check: 1289 * 1290 * Drivers should check plane specific constraints in this hook. 1291 * 1292 * When using drm_atomic_helper_check_planes() plane's @atomic_check 1293 * hooks are called before the ones for CRTCs, which allows drivers to 1294 * request shared resources that the CRTC controls here. For more 1295 * complicated dependencies the driver can call the provided check helpers 1296 * multiple times until the computed state has a final configuration and 1297 * everything has been checked. 1298 * 1299 * This function is also allowed to inspect any other object's state and 1300 * can add more state objects to the atomic commit if needed. Care must 1301 * be taken though to ensure that state check and compute functions for 1302 * these added states are all called, and derived state in other objects 1303 * all updated. Again the recommendation is to just call check helpers 1304 * until a maximal configuration is reached. 1305 * 1306 * This callback is used by the atomic modeset helpers, but it is 1307 * optional. 1308 * 1309 * NOTE: 1310 * 1311 * This function is called in the check phase of an atomic update. The 1312 * driver is not allowed to change anything outside of the 1313 * &drm_atomic_state update tracking structure. 1314 * 1315 * RETURNS: 1316 * 1317 * 0 on success, -EINVAL if the state or the transition can't be 1318 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an 1319 * attempt to obtain another state object ran into a &drm_modeset_lock 1320 * deadlock. 1321 */ 1322 int (*atomic_check)(struct drm_plane *plane, 1323 struct drm_atomic_state *state); 1324 1325 /** 1326 * @atomic_update: 1327 * 1328 * Drivers should use this function to update the plane state. This 1329 * hook is called in-between the &drm_crtc_helper_funcs.atomic_begin and 1330 * drm_crtc_helper_funcs.atomic_flush callbacks. 1331 * 1332 * Note that the power state of the display pipe when this function is 1333 * called depends upon the exact helpers and calling sequence the driver 1334 * has picked. See drm_atomic_helper_commit_planes() for a discussion of 1335 * the tradeoffs and variants of plane commit helpers. 1336 * 1337 * This callback is used by the atomic modeset helpers, but it is optional. 1338 */ 1339 void (*atomic_update)(struct drm_plane *plane, 1340 struct drm_atomic_state *state); 1341 1342 /** 1343 * @atomic_enable: 1344 * 1345 * Drivers should use this function to unconditionally enable a plane. 1346 * This hook is called in-between the &drm_crtc_helper_funcs.atomic_begin 1347 * and drm_crtc_helper_funcs.atomic_flush callbacks. It is called after 1348 * @atomic_update, which will be called for all enabled planes. Drivers 1349 * that use @atomic_enable should set up a plane in @atomic_update and 1350 * afterwards enable the plane in @atomic_enable. If a plane needs to be 1351 * enabled before installing the scanout buffer, drivers can still do 1352 * so in @atomic_update. 1353 * 1354 * Note that the power state of the display pipe when this function is 1355 * called depends upon the exact helpers and calling sequence the driver 1356 * has picked. See drm_atomic_helper_commit_planes() for a discussion of 1357 * the tradeoffs and variants of plane commit helpers. 1358 * 1359 * This callback is used by the atomic modeset helpers, but it is 1360 * optional. If implemented, @atomic_enable should be the inverse of 1361 * @atomic_disable. Drivers that don't want to use either can still 1362 * implement the complete plane update in @atomic_update. 1363 */ 1364 void (*atomic_enable)(struct drm_plane *plane, 1365 struct drm_atomic_state *state); 1366 1367 /** 1368 * @atomic_disable: 1369 * 1370 * Drivers should use this function to unconditionally disable a plane. 1371 * This hook is called in-between the 1372 * &drm_crtc_helper_funcs.atomic_begin and 1373 * drm_crtc_helper_funcs.atomic_flush callbacks. It is an alternative to 1374 * @atomic_update, which will be called for disabling planes, too, if 1375 * the @atomic_disable hook isn't implemented. 1376 * 1377 * This hook is also useful to disable planes in preparation of a modeset, 1378 * by calling drm_atomic_helper_disable_planes_on_crtc() from the 1379 * &drm_crtc_helper_funcs.disable hook. 1380 * 1381 * Note that the power state of the display pipe when this function is 1382 * called depends upon the exact helpers and calling sequence the driver 1383 * has picked. See drm_atomic_helper_commit_planes() for a discussion of 1384 * the tradeoffs and variants of plane commit helpers. 1385 * 1386 * This callback is used by the atomic modeset helpers, but it is 1387 * optional. It's intended to reverse the effects of @atomic_enable. 1388 */ 1389 void (*atomic_disable)(struct drm_plane *plane, 1390 struct drm_atomic_state *state); 1391 1392 /** 1393 * @atomic_async_check: 1394 * 1395 * Drivers should set this function pointer to check if the plane's 1396 * atomic state can be updated in a async fashion. Here async means 1397 * "not vblank synchronized". 1398 * 1399 * This hook is called by drm_atomic_async_check() to establish if a 1400 * given update can be committed asynchronously, that is, if it can 1401 * jump ahead of the state currently queued for update. 1402 * 1403 * RETURNS: 1404 * 1405 * Return 0 on success and any error returned indicates that the update 1406 * can not be applied in asynchronous manner. 1407 */ 1408 int (*atomic_async_check)(struct drm_plane *plane, 1409 struct drm_atomic_state *state); 1410 1411 /** 1412 * @atomic_async_update: 1413 * 1414 * Drivers should set this function pointer to perform asynchronous 1415 * updates of planes, that is, jump ahead of the currently queued 1416 * state and update the plane. Here async means "not vblank 1417 * synchronized". 1418 * 1419 * This hook is called by drm_atomic_helper_async_commit(). 1420 * 1421 * An async update will happen on legacy cursor updates. An async 1422 * update won't happen if there is an outstanding commit modifying 1423 * the same plane. 1424 * 1425 * When doing async_update drivers shouldn't replace the 1426 * &drm_plane_state but update the current one with the new plane 1427 * configurations in the new plane_state. 1428 * 1429 * Drivers should also swap the framebuffers between current plane 1430 * state (&drm_plane.state) and new_state. 1431 * This is required since cleanup for async commits is performed on 1432 * the new state, rather than old state like for traditional commits. 1433 * Since we want to give up the reference on the current (old) fb 1434 * instead of our brand new one, swap them in the driver during the 1435 * async commit. 1436 * 1437 * FIXME: 1438 * - It only works for single plane updates 1439 * - Async Pageflips are not supported yet 1440 * - Some hw might still scan out the old buffer until the next 1441 * vblank, however we let go of the fb references as soon as 1442 * we run this hook. For now drivers must implement their own workers 1443 * for deferring if needed, until a common solution is created. 1444 */ 1445 void (*atomic_async_update)(struct drm_plane *plane, 1446 struct drm_atomic_state *state); 1447 1448 /** 1449 * @get_scanout_buffer: 1450 * 1451 * Get the current scanout buffer, to display a message with drm_panic. 1452 * The driver should do the minimum changes to provide a buffer, 1453 * that can be used to display the panic screen. Currently only linear 1454 * buffers are supported. Non-linear buffer support is on the TODO list. 1455 * The device &dev.mode_config.panic_lock is taken before calling this 1456 * function, so you can safely access the &plane.state 1457 * It is called from a panic callback, and must follow its restrictions. 1458 * Please look the documentation at drm_panic_trylock() for an in-depth 1459 * discussions of what's safe and what is not allowed. 1460 * It's a best effort mode, so it's expected that in some complex cases 1461 * the panic screen won't be displayed. 1462 * The returned &drm_scanout_buffer.map must be valid if no error code is 1463 * returned. 1464 * 1465 * Return: 1466 * %0 on success, negative errno on failure. 1467 */ 1468 int (*get_scanout_buffer)(struct drm_plane *plane, 1469 struct drm_scanout_buffer *sb); 1470 1471 /** 1472 * @panic_flush: 1473 * 1474 * It is used by drm_panic, and is called after the panic screen is 1475 * drawn to the scanout buffer. In this function, the driver 1476 * can send additional commands to the hardware, to make the scanout 1477 * buffer visible. 1478 * It is only called if get_scanout_buffer() returned successfully, and 1479 * the &dev.mode_config.panic_lock is held during the entire sequence. 1480 * It is called from a panic callback, and must follow its restrictions. 1481 * Please look the documentation at drm_panic_trylock() for an in-depth 1482 * discussions of what's safe and what is not allowed. 1483 */ 1484 void (*panic_flush)(struct drm_plane *plane); 1485 }; 1486 1487 /** 1488 * drm_plane_helper_add - sets the helper vtable for a plane 1489 * @plane: DRM plane 1490 * @funcs: helper vtable to set for @plane 1491 */ drm_plane_helper_add(struct drm_plane * plane,const struct drm_plane_helper_funcs * funcs)1492 static inline void drm_plane_helper_add(struct drm_plane *plane, 1493 const struct drm_plane_helper_funcs *funcs) 1494 { 1495 plane->helper_private = funcs; 1496 } 1497 1498 /** 1499 * struct drm_mode_config_helper_funcs - global modeset helper operations 1500 * 1501 * These helper functions are used by the atomic helpers. 1502 */ 1503 struct drm_mode_config_helper_funcs { 1504 /** 1505 * @atomic_commit_tail: 1506 * 1507 * This hook is used by the default atomic_commit() hook implemented in 1508 * drm_atomic_helper_commit() together with the nonblocking commit 1509 * helpers (see drm_atomic_helper_setup_commit() for a starting point) 1510 * to implement blocking and nonblocking commits easily. It is not used 1511 * by the atomic helpers 1512 * 1513 * This function is called when the new atomic state has already been 1514 * swapped into the various state pointers. The passed in state 1515 * therefore contains copies of the old/previous state. This hook should 1516 * commit the new state into hardware. Note that the helpers have 1517 * already waited for preceding atomic commits and fences, but drivers 1518 * can add more waiting calls at the start of their implementation, e.g. 1519 * to wait for driver-internal request for implicit syncing, before 1520 * starting to commit the update to the hardware. 1521 * 1522 * After the atomic update is committed to the hardware this hook needs 1523 * to call drm_atomic_helper_commit_hw_done(). Then wait for the update 1524 * to be executed by the hardware, for example using 1525 * drm_atomic_helper_wait_for_vblanks() or 1526 * drm_atomic_helper_wait_for_flip_done(), and then clean up the old 1527 * framebuffers using drm_atomic_helper_cleanup_planes(). 1528 * 1529 * When disabling a CRTC this hook _must_ stall for the commit to 1530 * complete. Vblank waits don't work on disabled CRTC, hence the core 1531 * can't take care of this. And it also can't rely on the vblank event, 1532 * since that can be signalled already when the screen shows black, 1533 * which can happen much earlier than the last hardware access needed to 1534 * shut off the display pipeline completely. 1535 * 1536 * This hook is optional, the default implementation is 1537 * drm_atomic_helper_commit_tail(). 1538 */ 1539 void (*atomic_commit_tail)(struct drm_atomic_state *state); 1540 1541 /** 1542 * @atomic_commit_setup: 1543 * 1544 * This hook is used by the default atomic_commit() hook implemented in 1545 * drm_atomic_helper_commit() together with the nonblocking helpers (see 1546 * drm_atomic_helper_setup_commit()) to extend the DRM commit setup. It 1547 * is not used by the atomic helpers. 1548 * 1549 * This function is called at the end of 1550 * drm_atomic_helper_setup_commit(), so once the commit has been 1551 * properly setup across the generic DRM object states. It allows 1552 * drivers to do some additional commit tracking that isn't related to a 1553 * CRTC, plane or connector, tracked in a &drm_private_obj structure. 1554 * 1555 * Note that the documentation of &drm_private_obj has more details on 1556 * how one should implement this. 1557 * 1558 * This hook is optional. 1559 */ 1560 int (*atomic_commit_setup)(struct drm_atomic_state *state); 1561 }; 1562 1563 #endif 1564